When processing mail, it may be desirable to sort the mail into a pre-defined sequence. One such application relates to sorting mail received by wholesale lockbox processing centers. A wholesale lockbox processing centers receives payments for numerous companies, e.g. 1000-2000 companies. Each company or account pays the wholesale lockbox processing centers a fee to process each payment and deposit the payment as soon as possible. Generally the wholesale lockbox processing center makes several trips to the Post Office each day to pick up the mail. Each time the wholesale lockbox processing center picks up a batch of mail, they attempt to process the batch right away without waiting for another batch.
Generally, the deposits are processed according to instructions from the account holder. The instructions are often fairly complex and different accounts generally have different instructions. Therefore, it is not efficient to have every operator learn the instructions for every account. To process the documents efficiently, each account is assigned to a particular operator or a group of operators. For instance, the mail for about 30 accounts may be assigned to a particular operator. Alternatively, the mail for about 200 accounts may be assigned to a group of seven or eight operators, referred to as a work group. This allows the operators to become proficient processing the mail for the accounts assigned to the operator or work group. Accordingly, the incoming mail is sorted and separated so that all of the mail for a particular account is grouped together and delivered to the assigned operator or work group.
Conventional manual sorting is done numerically based on the P.O. Box number of the envelope. The process requires as many sort bins as accounts, and is usually done in two passes. For example, if there are 1000 accounts, the manual sorting uses 1000 bins. The first pass separates the envelopes into a relatively small number of piles of envelopes, for example 10 to 15 piles. Depending on the numbering system of the P.O. Boxes, the first sort can be as simple as using the first digit of a three digit P.O. Box number to create ten piles of one hundred P.O. Boxes.
The second pass typically requires sorting to numerous bins and is considerably slower than the first pass. During the second pass, the envelopes are usually sorted into 10 by 10 sort racks, which have 10 rows of 10 columns of bins. In the example of 1000 accounts, there will be 10 such sort racks, each having 100 bins. Each envelope is examined and placed into the appropriate bin in the appropriate sort rack.
The second pass results in the envelopes being sorted into numerical order according to the P.O. Box number. For instance, in the example of a batch of mail having three digit P.O. Box numbers, the batch of envelopes is separated into 10 piles of envelopes according to the first digit of the P.O. Box number. During the second pass each of the 10 piles is sorted separately. When processing the first pile of envelopes, the envelopes are placed into the individual bins in the first sort rack according to the second two digits of the P.O. Box number. For instance, the envelopes for P.O. Box 001 are placed in the second bin in the first row of the first sort rack and the envelopes for P.O. Box 111 are placed in the second bin of the second row of the sort rack. All of the envelopes in the first pile are sorted in this manner. The operator then sorts the remaining piles of documents into the bins of the other nine sort racks in a similar manner.
If the accounts are assigned to operators or work groups in numerical order, then the documents are ready to be distributed to the work groups after the second pass of the manual sorting. The envelopes are removed from the bins in order so that the envelopes in the sort bins are maintained in sequential order according to P.O. Box number. Frequently when the operator removes the envelopes from a particular bin, the operator will put a rubber band around the envelopes so that all of the envelopes for a particular account are grouped together and separated from other accounts.
Although it is possible to have the accounts assigned to the work groups in numerical order, the accounts for a work group are generally not sequential according to P.O. Box number. This is due to adding and deleting customers over the years. Therefore, after the documents are sorted into numerical order according to account, the documents are further sorted by work group. One manner for doing this is to color-code the individual bins of the sort racks according to work group. For instance, all of the bins for receiving documents for the first work group could be tagged with a yellow label. After the second pass of the manual process sorting, the operator removes the documents from the yellow labeled bins in order. In other words if the first work group includes P.O. Box numbers 001-050, 123-150, and 300-327, the operator removes the documents from the appropriate bins so that the documents are in order from lowest P.O. Box number to highest P.O. Box number.
Such a manual sorting system is labor-intensive and requires significant room for all of the sort bins. Accordingly, an efficient automated process for sorting the documents is desirable. A semi-automated process has been utilized, but the known systems require utilization of a significant number of receiving bins for the automated sorter. For instance, the known semi-automated system may utilize upwards of 50 bins. In addition, the semi-automated process rejects a significant number of documents. These documents are typically processed according to the manual system described above.